The invention relates to a system of structural shapes for transmissions of vehicles.
The heavy costs compel manufacturers of transmissions to implement the necessary variants of a range of products with a minimum of different structural parts. Not only the variable cost of products is decisive, but also the complexity of costs resulting from the multiplicity of parts.
Changes in the internal combustion engines due to the introduction of the electronic injection techniques and the need of optimal solutions regarding costs for the different operation requirements of the vehicles always leads to different products. For example, in the class of medium and heavy trucks the gear range desired works with the following requirements:
12 gears, finely stepped in the upper gears;
optionally direct speed or high speed;
the same or similar conditions of the different gears;
10 gears with less fine grading;
broad torque ranges from about 1000 Nm to about 3000 Nm;
all products manually shifted, alternatively partly and/or fully automated.
A solution known already for use of similar parts in different transmissions is shown in the Applicant""s ECOSPLIT-16-gear transmission disclosed, e.g. in the publication Johannes Looman""s Zahnradgetrieb, third edition, Springer Publishing House, Berlin Heidelberg 1996 on pages 264 ff in different shapes. The same transmission with different wheel widths leads to transmission of torques of different magnitude. Different ratio series result in designs for direct-speed of high-speed versions. Adaptations can be made by changing the lengths of the wheels, shafts, housing gear selection, etc. Additional aggregates like can result in a change of the housing and of the driving teeth. The multiplicity of products used leads to undesirably high logistic costs and costs of adaptation to the respective individual situations. DE 41 29 290 A1 has disclosed a transmission line of products in a multi-gear transmission for reducing the multiplicity of parts for different admissible input torques. But here are provided only transmissions having the same number of ratio steps. The transmission lines of products do not concern any transmission with a different number of gears.
The transmissions often have versions with two different ratio series. This is offered by transmission manufacturers so that the vehicle manufacturers have available transmissions of equal structure which are adaptable to different utilizations of the vehicles. Thus, transmission in high-speed and direct-speed versions, e.g. can be built which are used in the cross-country or on the road.
The problem on which this invention is based is to overcome the existing problems and high costs and to show a system of structural parts for equivalent uses which are interchangeable for different transmissions having different numbers of gears.
It is proposed to provide a line of products of transmissions in a manner such that, departing from a basic variant which has a specific arrangement of gear wheel pairs, one other variant can be produced by changing or adding in the form of a modular system only one gear wheel pair. Thereby can be obtained a modified total ratio of the transmission either by maintaining the former number of ratio steps or by a higher number of ratio steps. In all cases, the gear wheels of the group transmission remain unchanged. All gear wheel pairs of the variant with the smallest number of reduction steps are kept in all variants.
The whole transmission consists of a multi-gear split gear part, a multi-gear main gear part and a multi-gear group transmission which are successively disposed in one line. The inventive system can be used both for transmissions having one countershaft and in transmissions having a load distribution over several, preferably two, countershafts. The group transmission preferably consists of a planetary transmission whose sun gear is driven by the main shaft of the transmission and whose planet carrier constitutes the output shaft of the transmission and whose planet carrier constitutes the output shaft of the transmission. The ring gear of the planetary transmission can optionally be coupled with the transmission housing or with the planet carrier to form different ratio steps. The basic variant is preferably formed by 8-gear variants. According to the inventive system, on the basis of the latter designs of 10-gear variants and 12-gear variants are advantageously formed.
As a basic condition, the ratio step i between all ratio steps is the same. The ratio step can also be provided as half ratio step xcfx860.5. The axial distances of the shafts in the transmissions are the same in all variants.
In an advantageous embodiment, the 12-gear variant has in comparison with the 10-gear variant an additional gear wheel pair shaped so that in the 12-gear transmission the ratio of the ninth gear is between the ratios of the gears 8 and 9 of the 10-gear transmission and the ratio of the eleventh gear is between the ratios of the gears 9 and 10 of the 10-gear transmission.
In another advantageous embodiment, it is proposed to build a high-speed variant of a transmission having the same number of ratios steps, to change one wheel pair of the main gear which does not constitute a constant wheel pair and to leave other wheel pairs of the transmission the same.
In one other advantageous embodiment, it is proposed to build a high-speed variant of a transmission having a number of ratio steps increased by two ratio steps, to add a wheel pair of the main gear and leave the same the other wheel pairs of the transmission.
Another advantageous embodiment comprises to build a high-speed variant of a transmission having a number of ratio steps increased by two ratio steps and formed from a direct-speed variant, the addition of a wheel pair to the main gear, the added wheel pair not constituting a wheel pair of a constant and the other wheel pairs of the transmission remaining the same.
In another advantageous embodiment, it is proposed to build a high-speed variant, to substitute for a wheel set of a constant a wheel set quicker by two ratio steps and to leave the same the other wheel pairs of the transmission.
One other advantageous embodiment proposes, in the manual gear shift of the transmission for changing the selector lever positions of a shift pattern, to dispose at least one gear wheel of the main gear upon the same shaft turned by 180 degrees around an imaginary axis. The imaginary axis is perpendicular to a longitudinal axis of the shaft.
In another advantageous embodiment, it is proposed that in a 12-gear transmission the ratio steps 1 to 8 and the reverse gear is manually shiftable and the ratio steps 9 to 12 automatedly shiftable and in the shift pattern of the transmission that a selector position is provided which marks the introduction of an automated gear shift mode.
A In another advantageous embodiment, it is proposed that in a 10-gear transmission the ratio steps 1 to 8 and the reverse gear is manually shiftable and the ratio steps 9 and 10 is automatedly shiftable and in the shift pattern of the transmission a selector lever position be provided which marks the introduction of an automated shift mode.
In still another advantageous embodiment, it is proposed that in a 10-gear transmission the ratio steps 1 to 6 and reverse gear is manually shiftable and the ratio steps 7 to 10 automatedly shiftable and in the shift pattern of the transmission a selector lever position is provided which marks the introduction of an automated gear shift mode.
For the above mentioned transmissions with automated shift mode, it is proposed as an advantageous design that the selector lever position for the automated shift mode be in an H- or HH-shift pattern in the outer right end of the selector gate.
Another advantageous shift pattern shows the selector lever position for the automated gear shift mode in an H- or HH-shift pattern at the end of an outer right shift gate.
Still another advantageous shift pattern shows the selector lever position for the automated gear shift mode in an H- or HH-shift pattern also in the outer right end of the selector gate, wherein to reach the selector lever position, there is provided in the selector gate a position in which is effected the gear shift of the range change group.
Still one other advantageous embodiment shows that the 12-gear variant, unlike the 10-gear variant, has an additional gear wheel pair which is shaped so that in the 12-gear transmission the ratio of the ninth gear is quicker by half a speed ratio change xcfx860.5 than the ratio of the eighth gear of the 10-gear variant and the ratio of the eleventh gear is quicker by half a speed ratio change than the ratio of the 10-gear variant.
Still another advantageous embodiment shows that the 12-gear variant, unlike the 10-gear variant, has an additional gear wheel pair shaped so that in the 12-gear transmission the ratio of the tenth gear is half of a speed ratio change xcfx860.5 quicker than the ratio of the ninth gear of the 10-gear variant and the ratio of the twelfth gear is quicker by half a speed ratio change than the ratio of the tenth gear of the 10-gear variant. Thereby the total spreading of the transmission is increased by one half xcfx860.5 a speed ratio change.
In another advantageous embodiment, it is proposed that in the partial gears a different number of identical countershafts is respectively provided, the wheel pairs in transmissions with different capacities having the same tooth widths and the housing and gear shifts being equal.